Thu·Jun 6, 2019Thursday·June 6, 2019

1. 01*

   Explicit spacetime symmetry breaking in matter: the reversed Vavilov-Čerenkov radiation

   O. J. Franca🇲🇽 · L. F. Urrutia🇲🇽 · Omar Rodríguez-Tzompantzi🇲🇽

   We show that reversed Vavilov-Čerenkov radiation occurs simultaneously with the forward output in naturally existing materials when an electric charge moves with a constant velocity perpendicular to the planar interface between two magnetoelectric media. Using the Green's function in the far-field approximation we calculate the angular distribution of the radiated energy per unit frequency obtaining a non-zero contribution in the backward direction.

   hep-phhep-th0 citations
2. 02*

   How to produce antinuclei from dark matter

   Julian Heeck🇺🇸 · Arvind Rajaraman🇺🇸

   We show how to produce antideuteron, antihelium, and other antinuclei in large fractions from the decays of a new particle $\varphi$ that carries baryon number. Close to threshold, the production of nuclear bound states is preferred over the decay into individual nucleons, effectively decoupling antinuclei and antiproton fluxes and allowing the former to dominate, in clear contrast to antimatter production via coalescence. $\varphi$ can either form dark matter itself or be produced by it, and can give rise to a potentially testable amount of antinuclei.

   hep-phastro-ph.HEJ.Phys.G(2020)·13 citations
3. 03*

   Neutrino oscillations in a trapping potential

   Lucas Johns🇺🇸

   A number of derivations of the standard neutrino oscillation formula are known, each one providing its own unique insights. Common to all treatments is the assumption that neutrinos propagate freely between source and detector, as indeed they do in all experiments thus far conducted. Here we consider how neutrinos oscillate when, contrary to the usual set-up, they are bound in a potential well. The focus in particular is on nonrelativistic neutrinos with quasi-degenerate masses, for which oscillations in free space are described by the same formula, to lowest order, as relativistic neutrinos. Trapping these particles engenders corrections to their oscillation frequencies because the interference terms are between discrete energy levels rather than continuous spectra. Especially novel is the frequency shift that occurs due to the dependence of the energy levels on the mass of the neutrino: this part of the correction is nonvanishing even in the extremely nonrelativistic limit, reflecting the fact that the neutrino mass states have different zero-point energies in the well. Building an apparatus that can trap neutrinos is a futuristic prospect to say the least, but these calculations nonetheless shine a light on certain basic aspects of the flavor-oscillation phenomenon.

   hep-phquant-phInt.J.Mod.Phys.A(2019)·1 citation
4. 04*

   Quark Flavour Dependence of the Shear Viscosity in a Quasiparticle Model

   Valeriya Mykhaylova🇵🇱 · Marcus Bluhm🇵🇱 · Krzysztof Redlich🇵🇱 · Chihiro Sasaki🇵🇱

   We study the temperature-dependence of the shear viscosity to entropy density ratio in pure Yang-Mills theory and in QCD with light and strange quarks within kinetic theory in the relaxation time approximation. As effective degrees of freedom in a deconfined phase we consider quasiparticle excitations with quark and gluon quantum numbers and dispersion relations that depend explicitly on the temperature. The quasiparticle relaxation times are obtained by computing the microscopic two-body scattering amplitudes for the elementary scatterings among the quasiparticles. For pure Yang-Mills theory we show that the shear viscosity to entropy density ratio exhibits a characteristic non-monotonicity with a minimum at the first-order phase transition. In the presence of dynamical quarks the ratio smoothens while still exhibiting a minimum near confinement. Furthermore, there is a significant increase of the shear viscosity to entropy density ratio in QCD resulting from the quark contributions. This observation differs from previously reported estimates based on functional methods but is in line with perturbative QCD expectations at higher temperatures.

   hep-phnucl-thPRD(2019)·39 citations
5. 05*

   Testing the W-exchange mechanism with two-body baryonic B decays

   Y.K. Hsiao🇨🇳 · Shang-Yuu Tsai🇨🇳 · Chong-Chung Lih🇹🇼 · Eduardo Rodrigues🇬🇧

   The role of $W$-exchange diagrams in baryonic $B$ decays is poorly understood, and often taken as insignificant and neglected. We show that charmful two-body baryonic $B\to {\mathbf{B}}_c{\bar{\mathbf{B}}}^{\prime }$ decays provide a good test-bed for the study of the $W$-exchange topology, whose contribution is found to be non-negligible; here ${\mathbf{B}}_c$ is an anti-triplet or a sextet charmed baryon, and ${\bar{\mathbf{B}}}^{\prime }$ an octet charmless (anti-)baryon. In particular, we calculate that $\mathcal{B}({\bar{B}}^0\to {\Sigma }_c^{+}\bar{p})=(2.9_{-0.9}^{+0.8})\times 10^{-6}$ in good agreement with the experimental upper bound. Its cousin ${\bar{B}}_s^0$ mode, ${\bar{B}}_s^0\to {\Lambda }_c^{+}\bar{p}$, is a purely $W$-exchange decay, hence is naturally suited for the study of the role of the $W$-exchange topology. We predict $\mathcal{B}({\bar{B}}_s^0\to {\Lambda }_c^{+}\bar{p})=(0.8\pm 0.3)\times 10^{-6}$, a relatively large branching ratio to be tested with a future measurement by the LHCb collaboration. Other predictions, such as $\mathcal{B}({\bar{B}}^0\to {\Xi }_c^{+}{\bar{\Sigma }}^{-})=(1.1\pm 0.4)\times 10^{-5}$, can be tested with future Belle II measurements.

   hep-phhep-exJHEP(2020)·25 citations
6. 06*

   A Simultaneous Study of Dark Matter and Phase Transition: Two-Scalar Scenario

   Karim Ghorbani🇮🇷 · Parsa Hossein Ghorbani🇮🇷

   The simplest extension of the Standard Model by only one real singlet scalar can explain the observed dark matter relic density while giving simultaneously a strongly first-order electroweak phase transition in the early universe. However, after imposing the invisible Higgs decay constraint from the LHC, the parameter space of the single scalar model shrinks to regions with only a few percent of the DM relic abundance and when adding the direct detection bound, e.g. from XENON100, it gets excluded completely. In this paper, we extend the Standard Model with two real guage singlet scalars, here $s$ and $s^{\prime }$, and show that the electroweak symmetry breaking may occur via different channels. Despite very restrictive first-order phase transition conditions for the two-scalar model in comparison to the single scalar model, there is a viable space of parameters in different phase transition channels that simultaneously explains a fraction or the whole dark matter relic density, a strongly first-order electroweak phase transition and still evading the direct detection bounds from the latest LUX/XENON experiments while respecting the invisible Higgs decay width constraint from the LHC.

   hep-phhep-thJHEP(2019)·24 citations
7. 07*

   Up-down asymmetries of charmed baryon three-body decays

   Jian-Yong Cen🇨🇳 · Chao-Qiang Geng🇨🇳 · Chia-Wei Liu🇹🇼 · Tien-Hsueh Tsai🇹🇼

   We study the up-down asymmetries in the three-body anti-triplet charmed baryon decays of ${\mathbf{B}}_{\mathbf{c}}\to {\mathbf{B}}_{\mathbf{n}}M{M}^{\prime }$ with the $SU(3{)}_f$ flavor symmetry, where ${\mathbf{B}}_{\mathbf{c}}$ presents the anti-triplet charmed baryon of $({\Xi }_c^0,-{\Xi }_c^{+},{\Lambda }_c^{+})$, while ${\mathbf{B}}_{\mathbf{n}}$ and $M^{{(}^{\prime })}$ denote octet baryon and meson states, respectively. By assuming the s-wave meson-pairs to be the dominant constituents in final state configurations, we can write the spin-dependent decay amplitude into parity-conserving and parity-violating parts, parametrized by 6 real parameters under $SU(3{)}_f$, respectively. Fitting these parameters by 16 experimental data points with the minimum ${\chi }^2$ method, we obtain that ${\chi }^2/d.o.f=2.4$. With the fitted parameters, we evaluate the up-down asymmetries along with the decay branching ratios of ${\mathbf{B}}_{\mathbf{c}}\to {\mathbf{B}}_{\mathbf{n}}M{M}^{\prime }$. Some of these up-down asymmetries are accessible to the experiments at BESIII, BELLE-II and LHCb.

   hep-phhep-exEPJC(2019)·27 citations
8. 08*

   An event generator for same-sign W-boson scattering at the LHC including electroweak corrections

   Mauro Chiesa🇩🇪 · Ansgar Denner🇩🇪 · Jean-Nicolas Lang🇨🇭 · Mathieu Pellen🇬🇧

   In this article we present an event generator based on the Monte Carlo program Powheg in combination with the matrix-element generator Recola. We apply it to compute NLO electroweak corrections to same-sign W-boson scattering, which have been shown to be large at the LHC. The event generator allows for the generation of unweighted events including the effect of the NLO electroweak corrections matched to a QED parton shower and interfaced to a QCD parton shower. In view of the expected experimental precision of future measurements, the use of such a tool will be indispensable.

   hep-phhep-exEPJC(2019)·50 citations
9. 09*

   A near-minimal leptoquark model for reconciling flavour anomalies and generating radiative neutrino masses

   Innes Bigaran🇦🇺 · John Gargalionis🇦🇺 · Raymond R. Volkas🇦🇺

   We introduce two scalar leptoquarks, the SU$(2{)}_L$ isosinglet denoted $\varphi \sim (3,1,-1/3)$ and the isotriplet $\phi \sim (3,3,-1/3)$, to explain observed deviations from the standard model in semi-leptonic $B$-meson decays. We explore the regions of parameter space in which this model accommodates the persistent tensions in the decay observables $R_{D^{(\ast )}}$, $R_{K^{(\ast )}}$, and angular observables in $b\to s\mu \mu$ transitions. Additionally, we exploit the role of these exotics in existing models for one-loop neutrino mass generation derived from $\Delta L=2$ effective operators. Introducing the vector-like quark $\chi \sim (3,2,-5/6)$ necessary for lepton-number violation, we consider the contribution of both leptoquarks to the generation of radiative neutrino mass. We find that constraints permit simultaneously accommodating the flavour anomalies while also explaining the relative smallness of neutrino mass without the need for cancellation between leptoquark contributions. A characteristic prediction of our model is a rate of muon--electron conversion in nuclei fixed by the anomalies in $b\to s\mu \mu$ and neutrino mass; the COMET experiment will thus test and potentially falsify our scenario. The model also predicts signatures that will be tested at the LHC and Belle II.

   hep-phJHEP(2019)·92 citations
10. 10*

    Chiral effective theories with a light scalar at one loop

    Oscar Cata🇩🇪 · Christoph Mueller🇩🇪

    There are indications that some theories with spontaneous symmetry breaking also feature a light scalar in their spectrum, with a mass comparable to the one of the Goldstone modes. In this paper, we perform the one-loop renormalization of a theory of Goldstone modes invariant under a chiral $SU(n)\times SU(n)$ symmetry group coupled to a generic scalar singlet. We employ the background field method, together with the heat kernel expansion, to get an expression for the effective action at one loop and single out the anomalous dimensions, which can be read off from the second Seeley-DeWitt coefficient. As a relevant application, we use our master formula to renormalize chiral-scale perturbation theory, an alternative to $SU(3)$ chiral perturbation theory where the $f_0(500)$ meson is interpreted as a dilaton. Based on our results, we briefly discuss strategies to test and discern both effective field theories using lattice simulations.

    hep-phhep-latNPB(2020)·51 citations
11. 11*

    HERAPDF2.0Jets NNLO (prel.), the completion of the HERAPDF2.0 family

    Amanda Cooper-Sarkar (H1 and ZEUS Collaborations)🇬🇧

    The HERAPDF2.0 family, introduced in 2015, is completed with fits HERAPDF2.0Jets NNLO (prel.) based on inclusive HERA data and selected jet production data. The result of a fit with the strong coupling constant, ${\alpha }_s(M_Z^2)$, free is ${\alpha }_s(M_Z^2)=0.1150\pm 0.0008{(\exp )}_{-0.0005}^{+0.0002}$ (model/parameterisation) $\pm 0.0006(\mathrm{hadronisation})\pm 0.0027(\mathrm{scale})$. Sets of parton density functions, PDFs, from fits with fixed ${\alpha }_s(M_Z^2)=0.115$ and ${\alpha }_s(M_Z^2)=0.118$ are presented and compared.

    hep-phPoS(2019)·3 citations
12. 12*

    Chemical freeze-out conditions and fluctuations of conserved charges in heavy-ion collisions within quantum van der Waals model

    R. Poberezhnyuk🇺🇦 · V. Vovchenko🇩🇪 · A. Motornenko🇩🇪 · M. I. Gorenstein🇺🇦 · H. Stoecker🇩🇪

    The chemical freeze-out parameters in central nucleus-nucleus collisions are extracted consistently from hadron yield data within the quantum van der Waals (QvdW) hadron resonance gas model. The beam energy dependences for skewness and kurtosis of net baryon, net electric, and net strangeness charges are predicted. The QvdW interactions in asymmetric matter, $Q/B\ne 0.5$, between (anti)baryons yield a non-congruent liquid-gas phase transition, together with a nuclear critical point (CP) with critical temperature of $T_c=19.5$ MeV. The nuclear CP yields the collision energy dependence of the skewness and the kurtosis to both deviate significantly from the ideal hadron resonance gas baseline predictions even far away, in $(T,{\mu }_B)$-plane, from the CP. These predictions can readily be tested by STAR and NA61/SHINE Collaborations at the RHIC BNL and the SPS CERN, respectively, and by HADES at GSI. The results presented here offer a broad opportunity for the search for signals of phase transition in dense hadronic matter at the future NICA and FAIR high intensity facilities.

    hep-phnucl-thPRC(2019)·44 citations
13. 13*

    The CPT-violating effects on neutron's gravitational bound state

    Zhi Xiao🇨🇳

    Analytical solutions with effective CPT-violating spin--gravity corrections to the neutron's gravitational bound states are obtained. The helicity-dependent phase evolution due to $\vec{\sigma }\cdot \overrightarrow{\stackrel{~}{b}}$ and $\vec{\sigma }\cdot \hat{\vec{p}}$ couplings not only leads to spin precession, %shown by the tip of the spin on the Bloch sphere,but also to transition-frequency shifts between different gravitational bound states. Utilizing transition frequencies measured in the qBounce experiment,\cite{GRS} we obtain the rough bound $|\overrightarrow{\stackrel{~}{b}}|<6.9\times 10^{-21}$GeV. Incorporating known systematic errors may lead to more robust and tighter constraints.

    hep-ph2 citations
14. 14*

    Searches for magnetic monopoles and others stable massive particles

    Maurizio Spurio🇮🇹

    The Standard Model (SM) of the microcosm provides an excellent description of the phenomena of the microcosm, with the triumph of the discovery of the Higgs boson. There are many reasons, however, to believe that the SM is incomplete and represents a valid theory at relatively low energies only. Of particular interest are the models based on complete symmetries, such as those attempting a true unification between leptons and quarks in terms of a single symmetry group (Grand Unified Theories, GUTs) and those attempting unification between fermions and bosons, such as the supersymmetry. This chapter is devoted to the description of stable and massive particles not predicted within the SM, their energy loss mechanisms and their searches in the cosmic radiation. The stability of these particles means that if they were produced at any time in the thermal history of the Universe, they would still be present as relic particles. Examples of stable massive particles discussed in this chapter include magnetic monopoles, strange quark matter and supersymmetric particles. In particular, we focus on the status of searches for magnetic monopoles (also inducing proton-decay processes), nuclearites and Q-balls in neutrino telescopes.

    hep-ph4 citations
15. 15*

    Icecube/DeepCore tests for novel explanations of the MiniBooNE anomaly

    Pilar Coloma🇪🇸

    While the low-energy excess observed at MiniBooNE remains unchallenged, it has become increasingly difficult to reconcile it with the results from other sterile neutrino searches and cosmology. Recently, it has been shown that non-minimal models with new particles in a hidden sector could provide a better fit to the data. As their main ingredients they require a GeV-scale $Z^{\prime }$, kinetically mixed with the photon, and an unstable heavy neutrino with a mass in the 150 MeV range that mixes with the light neutrinos. In this letter we point out that atmospheric neutrino experiments (and, in particular, IceCube/DeepCore) could probe a significant fraction of the parameter space of such models by looking for an excess of "double-bang" events at low energies, as proposed in our previous work (arXiv:1707.08573). Such a search would probe exactly the same production and decay mechanisms required to explain the anomaly.

    hep-phhep-exEPJC(2019)·26 citations
16. 16*

    Off-shell quark bilinear operator Green's functions at two loops

    J.A. Gracey🇬🇧

    We construct the two loop Green's functions for a quark bilinear operator inserted at non-zero momentum in a quark 2-point function for the most general off-shell configuration. In particular we consider the quark mass operator, vector and tensor currents as well as the second moment of the flavour non-singlet Wilson operator.

    hep-phhep-latPRD(2019)·2 citations
17. 17*

    New Features in FeynArts & Friends, and how they got used in FeynHiggs

    T. Hahn🇩🇪

    This note gives an update on recent developments in FeynArts, FormCalc, and LoopTools, and shows how the new features were used in making the latest version of FeynHiggs.

    hep-phJ.Phys.Conf.Ser.(2020)·1 citation
18. 18*

    Signatures of Supersymmetry in Neutrino Telescopes

    P. S. Bhupal Dev🇺🇸

    We review the prospects of probing $R$-parity violating Supersymmetry (RPV SUSY) at neutrino telescopes using some of the highest energy particles given to us by Nature. The presence of RPV interactions involving ultra-high energy neutrinos with Earth-matter can lead to resonant production of TeV-scale SUSY partners of the SM quarks and leptons (squarks and sleptons), thereby giving rise to potentially anomalous behavior in the event spectrum observed by large-volume neutrino detectors, such as IceCube, as well as balloon-borne cosmic ray experiments, such as ANITA. Using the ultra-high energy neutrino events observed recently at IceCube, with the fact that for a given power-law flux of astrophysical neutrinos, there is no statistically significant deviation in the current data from the Standard Model expectations, we derive robust upper limits on the RPV couplings as a function of the resonantly-produced squark mass, independent of the other unknown model parameters, as long as the squarks decay dominantly to two-body final states involving leptons and quarks through the RPV couplings. Also, we discuss RPV SUSY interpretations of the recent anomalous, upward-going EeV air showers observed at ANITA, in terms of long-lived charged or neutral next-to-lightest SUSY particles.

    hep-phProbing Particle Physics with Neutrino Te…·5 citations
19. 19*

    Pseudo-Goldstone dark matter confronts cosmic ray and collider anomalies

    James M. Cline🇨🇦 · Takashi Toma🇨🇦

    Persistent excesses in the spectra of gamma rays from the galactic center and cosmic ray antiprotons can be explained by dark matter of mass $50\sim 65$\,GeV annihilating into $b$ quarks, but this is typically hard to reconcile with direct detection constraints. We resolve this tension using a simple class of models, where dark matter is a pseudo-Nambu-Goldstone boson, having naturally momentum-suppressed couplings to nuclei. Exploring the parameter space of the model, we find that it can explain the cosmic ray anomalies while remaining compatible with constraints from the relic abundance and annihilation in dwarf spheroidal galaxies. In certain regions of parameter space, the Higgs-dark matter coupling can help stabilize the Higgs potential up to the Planck scale. The scalar partner of the dark matter is an extra Higgs boson, that can explain a tentative diphoton excess observed by CMS, and an excess of $b\bar{b}$ signal from LEP, if its mass is $\sim 96$\,GeV and the model is extended to include a heavy scalar quark. This extended model predicts a monochromatic gamma-ray line near 64 GeV, at a level close to current experimental sensitivity, from dark matter annihilations in the galaxy.

    hep-phastro-ph.COastro-ph.HEPRD(2019)·84 citations
20. 20*

    Nuclear Effects and CP Sensitivity at DUNE

    Srishti Nagu🇮🇳 · Jaydip Singh🇮🇳 · Jyotsna Singh🇮🇳

    The precise measurement of neutrino oscillation parameters is one of the highest priorities in neutrino oscillation physics. To achieve the desired precision, it is necessary to reduce the systematic uncertainties related to neutrino energy reconstruction. An error in energy reconstruction is propagated to all the oscillation parameters, hence a careful estimation of neutrino energy is required. To increase the statistics, neutrino oscillation experiments use heavy nuclear targets like Argon(Z=18). The use of these nuclear targets introduces nuclear effects that severely impact the neutrino energy reconstruction which in turn poses influence in the determination of neutrino oscillation parameters. In this work, we have tried to quantify nuclear effects on the determination of CP phase at DUNE using final state interactions.

    hep-phAdv.High Energy Phys.(2020)·11 citations
21. 21*

    The Bi-Spinor Standard Model with 3 Generations

    A. Jourjine🇩🇪

    We show that if two of four generations of the bi-spinor Standard Model are mass-degenerate or sufficiently close in mass only three generations can be observed. We argue that the Standard Model and its bi-spinor analog are indistinguishable on the level of the electroweak precision variables S, T, U. As a result the bi-spinor Standard Model, which describes experimental observed textures of flavor mixing matrices is a better fit to the data then the Standard Model, where the textures are arbitrary.

    hep-ph1 citation
22. 22*

    Light Hidden Mesons through the Z Portal

    Hsin-Chia Cheng🇺🇸 · Lingfeng Li🇨🇳 · Ennio Salvioni🇩🇪 · Christopher B. Verhaaren🇺🇸

    Confining hidden sectors are an attractive possibility for physics beyond the Standard Model (SM). They are especially motivated by neutral naturalness theories, which reconcile the lightness of the Higgs with the strong constraints on colored top partners. We study hidden QCD with one light quark flavor, coupled to the SM via effective operators suppressed by the mass $M$ of new electroweak-charged particles. This effective field theory is inspired by a new tripled top model of supersymmetric neutral naturalness. The hidden sector is accessed primarily via the $Z$ and Higgs portals, which also mediate the decays of the hidden mesons back to SM particles. We find that exotic $Z$ decays at the LHC and future $Z$ factories provide the strongest sensitivity to this scenario, and we outline a wide array of searches. For a larger hidden confinement scale $\Lambda \sim O(10)\mathrm{GeV}$, the exotic $Z$ decays dominantly produce final states with two hidden mesons. ATLAS and CMS can probe their prompt decays up to $M\sim 3\mathrm{TeV}$ at the high luminosity phase, while a TeraZ factory would extend the reach up to $M\sim 20\mathrm{TeV}$ through a combination of searches for prompt and displaced signals. For smaller $\Lambda \sim O(1)\mathrm{GeV}$, the $Z$ decays to the hidden sector produce jets of hidden mesons, which are long-lived. LHCb will be a powerful probe of these emerging jets. Furthermore, the light hidden vector meson could be detected by proposed dark photon searches.

    hep-phhep-exJHEP(2019)·43 citations
23. 23*

    The Warped Dark Sector

    Philippe Brax🇫🇷 · Sylvain Fichet🇧🇷 · Philip Tanedo🇺🇸

    Five-dimensional braneworld constructions in anti-de Sitter space naturally lead to dark sector scenarios in which parts of the dark sector vanish at high 4d momentum or temperature. In the language of modified gravity, such feature implies a new mechanism for hiding light scalars, as well as the possibility of UV-completing chameleon-like effective theories. In the language of dark matter phenomenology, the high-energy behaviour of the mediator sector changes dark matter observational complementarity. A multitude of signatures---including exotic ones---are present from laboratory to cosmologic scales, including long-range forces with non-integer behaviour, periodic signals at colliders, `soft bombs' events well-known from conformal theories, as well as a dark phase transition and a typically small amount of dark radiation.

    hep-phastro-ph.COgr-qcPLB(2019)·55 citations
24. 24*

    Multiple modular symmetries as the origin of flavour

    Ivo de Medeiros Varzielas🇵🇹 · Stephen F. King🇬🇧 · Ye-Ling Zhou🇬🇧

    We develop a general formalism for multiple moduli and their associated modular symmetries. We apply this formalism to an example based on three moduli with finite modular symmetries $S_4^A$, $S_4^B$ and $S_4^C$, associated with two right-handed neutrinos and the charged lepton sector, respectively. The symmetry is broken by two bi-triplet scalars to the diagonal $S_4$ subgroup. The low energy effective theory involves the three independent moduli fields ${\tau }_A$, ${\tau }_B$ and ${\tau }_C$, which preserve the residual modular subgroups $Z_3^A$, $Z_2^B$ and $Z_3^C$, in their respective sectors, leading to trimaximal TM${}_1$ lepton mixing, consistent with current data, without flavons.

    hep-phPRD(2020)·140 citations
25. 25*

    Variable Planck mass from the gauge invariant flow equation

    Christof Wetterich🇩🇪 · Masatoshi Yamada🇩🇪

    Using the gauge invariant flow equation for quantum gravity we compute how the strength of gravity depends on the length or energy scale. The fixed point value of the scale-dependent Planck mass in units of the momentum scale has an important impact on the question, which parameters of the Higgs potential can be predicted in the asymptotic safety scenario for quantum gravity? For the standard model and a large class of theories with additional particles the quartic Higgs coupling is an irrelevant parameter at the ultraviolet fixed point. This makes the ratio between the Higgs boson and the top-quark mass predictable.

    ↳ hep-thgr-qchep-phPRD(2019)·79 citations
26. 26*

    Status of Light Sterile Neutrino Searches

    Sebastian Böser🇩🇪 · Christian Buck🇩🇪 · Carlo Giunti🇮🇹 · Julien Lesgourgues🇩🇪 · Livia Ludhova🇩🇪 · Susanne Mertens🇩🇪 · Anne Schukraft🇺🇸 · Michael Wurm🇩🇪

    A number of anomalous results in short-baseline oscillation may hint at the existence of one or more light sterile neutrino states in the eV mass range and have triggered a wave of new experimental efforts to search for a definite signature of oscillations between active and sterile neutrino states. The present paper aims to provide a comprehensive review on the status of light sterile neutrino searches in mid-2019: we discuss not only the basic experimental approaches and sensitivities of reactor, source, atmospheric, and accelerator neutrino oscillation experiments but also the complementary bounds arising from direct neutrino mass experiments and cosmological observations. Moreover, we review current results from global oscillation analyses that include the constraints set by running reactor and atmospheric neutrino experiments. They permit to set tighter bounds on the active-sterile oscillation parameters but as yet are not able to provide a definite conclusion on the existence of eV-scale sterile neutrinos.

    ↳ hep-exastro-ph.COhep-phphysics.ins-detPPNP(2020)·259 citations
27. 27*

    Probing Dynamics of Boson Stars by Fast Radio Bursts and Gravitational Wave Detection

    Gongjun Choi🇨🇳 · Hong-Jian He🇨🇳 · Enrico D. Schiappacasse🇨🇳

    Boson stars may consist of a new type of light singlet scalar particles with nontrivial self-interactions, and may compose a fraction of the dark matter in the Universe. In this work, we study the dynamics of boson stars with Liouville and logarithmic scalar self-interaction potentials as benchmarks. We perform a numerical analysis as well as a semi-analytic study on how the compactness and the total mass will deviate from that of the usual boson stars formed with a quartic repulsive self-interaction. We apply the recently suggested Swampland conjecture to examine whether boson stars with such benchmark potentials belong to the Landscape of a quantum gravity. Using the mass constraint on the macroscopic compact halo object (MACHO) and the cold dark matter (CDM) isocurvature mode constraint from the cosmic microwave background (CMB), we derive the allowed mass range of scalar particles which compose the boson star. We further analyze applications of the lensing of fast radio bursts (FRBs) and the gravitational wave (GW) detection to probe the presence of such boson stars and constrain the parameter space of their corresponding models. We discuss how the two types of boson star potentials can be discriminated by the FRB and GW measurements.

    ↳ astro-ph.COgr-qchep-phJCAP(2019)·37 citations
28. 28*

    Perturbations against a Q-ball. II. Contribution of nonoscillation modes

    Mikhail N. Smolyakov🇷🇺

    In the present paper, discussion of perturbations against a Q-ball solution is continued. It is shown that in order to correctly describe perturbations containing nonoscillation modes, it is also necessary to consider nonlinear equations of motion for the perturbations, like in the case of oscillation modes only. It is also shown that the additivity of the charge and the energy of different modes holds for the most general nonlinear perturbation consisting of oscillation and nonoscillation modes.

    ↳ hep-thhep-phPRD(2019)·9 citations
29. 29*

    On hilltop and brane inflation after Planck

    Renata Kallosh🇺🇸 · Andrei Linde🇺🇸

    Hilltop inflation models are often described by potentials $V=V_0(1-\frac{{\varphi }^n}{m^n}+...)$. The omitted terms indicated by ellipsis do not affect inflation for $m\lesssim 1$, but the most popular models with $n=2$ and $4$ for $m\lesssim 1$ are ruled out observationally. Meanwhile in the large $m$ limit the results of the calculations of the tensor to scalar ratio $r$ in the models with $V=V_0(1-\frac{{\varphi }^n}{m^n})$, for all $n$, converge to $r=4/N\lesssim 0.07$, as in chaotic inflation with $V\sim \varphi$, suggesting a reasonably good fit to the Planck data. We show, however, that this is an artifact related to the inconsistency of the model $V=V_0(1-\frac{{\varphi }^n}{m^n})$ at $\varphi >m$. Consistent generalizations of this model in the large $m$ limit typically lead to a much greater value $r=8/N$, which negatively affects the observational status of hilltop inflation. Similar results are valid for D-brane inflation with $V=V_0(1-\frac{m^n}{{\varphi }^n})$, but consistent generalizations of D-brane inflation models may successfully complement $\alpha$-attractors in describing most of the area in the ($n_s$, $r$) space favored by Planck 2018.

    ↳ hep-thastro-ph.COgr-qchep-phJCAP(2019)·53 citations
30. 30*

    BPS solutions for generalised Wess-Zumino models and their applications

    Steven Abel🇬🇧 · Quentin Bonnefoy🇫🇷 · Debtosh Chowdhury🇫🇷

    We present BPS solutions to a general class of Wess-Zumino models which extend previous results in the literature. We discuss their relation to amplitudes on threshold, and their application to scalar domain walls in Supersymmetric QCD. We also find partial expressions for Wess-Zumino models with softly broken supersymmetry.

    ↳ hep-thhep-phJHEP(2019)·2 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.